Best solution would be a clown loach or 2 or 3 depending on the tank size.
As a member brought up, All that benificial bactetria just got killed.
If you broke the whole tank down filter,gravel,decor and washed EVERYTHING you may go through the new tank cycle.
NEVER do all at once: clean gravel,filter(s),wash plants,wash decor,and most important No,No, don't wash the gravel. By doing this you are killing off al the bacteria which help maintain a healthy tank. Best soulution is to syphon the gravel. If you have a wide enough syphon hose you can even graze the hose along the gravel and manualy remove a good # of the snails.
Not trying to worry you instead safe you alot of grief and disapoinment in the long run.
Though if you left something unwashed and didn't do the filter(s)also you may run less a chance of youre tank taking a crash.
Now, what kind of snails where they? You know?
There are several types some of which are VERY distructive with plants and a few that are not as bad. I currently have 60+ tanks and most have some type of snails. This helps control any acess alage and food thats left uneaten if hungry enough. Though most plants I keep are anubias and VERY risistant to snails i rarely have a epedemic. Even in the tanks planted with softer south american and asian plants.
And if so i move a clown loach and watch as he / she chomps away. Normaly a fair size clown loach can clear / make a big dent in a snail population.
The downfall to the clown loachs is some / most are shy and seldomly come around. NOT all though.
I have a few and some are very shy hidding down the sponge filter tube inside the sponge. ? go figure thats his home.
Many times I thought he was gone then peek a fin you see his nose sticking out of the sponge. This one is just silly because he / she is the most active person friendly loach I got.
While another wants nothing to do with non fins having humans nor reflections across the tank. My point they don't all shy away and hide. And they do prffer to be in groups if poss.
They are pretty testy when it comes to temp changes and are prone to ick up if water temps change drasticly. Just a tid bit.
Just my 2 fins worth.
Danny
Hi all Thought I would tell how I got rid of my pomd snails when chems would'nt work. I decided to do this extrem method when all other ways failed. I hve been trying to get rid of the snails for months using chems bleach everything. When they caused My 3 A.borellii spawns to fail So I got mad. And broke down the tank removed the fish and plants Drained the water through strainer was going to use half to cycle tank. Then I boiled 2 large posts of water poured the water in the tank and cooked them washed the tank ,sand, equip everything with boiling water. I could Almost hear them scream LMAO hehehe. I then made up a 1to20 bleach solution then dipped my plants in it. Then reset up my tank Put my fish and plants back in and no more snails halaluya. did this to my 2 10 gal apisto tanks. My A.cacatuoides are getting ready to spawn and my A. borellii Spawned the next day have got 2 females guarding eggs should see fry around thur or fri. So If you have major pond snail infestation COOK em I did.LOL Sincerely Curtis 
B) 
To me, they are evil little creatures. There is no rationale to my "logic" but that's just the way I see those slimy little buggers 
Ok Ok Man first off tryied loaches they worked for short time I didn't get clowns they get to big so I got skunks inst. They turned out to be to agressive for breeding tank so I moved them. Sails came back loaches don't kill all. tryied chems no luck Tryied the vac , crushing, ect . Now as for killing benifical bac and dead snail corpses. I cleaned and rinsed tank and gravel afterwards. But i didn't throw away all water that was in the tank before just strained it and mixed wiith new conditioned water and re set up tank hence no cycleing. Finally the type of snail was the little pond snail that is nothing more than a pest and food which do no alge control and over populate like crazy and eat mostly oganics like fresh laid eggs. I hope this explains and ansers. And I really hate Snails they are only good for fishbait and crushing personal opinion of course. Sincerely Curtis 
