Well I see the problem with the 10 gallon so I have an idea. The 40 is empty now right? Any chance you could empty out the 10 and wash it out a bit and then move the 40's filter into it? Then you'll have a clean tank, hopefuly not infected with the worms, but you'll also not need to worry about water quality and you can continue treating the platy which you say is stressed in there. Leave the others in the bowls for as long as they look ok. The 10 is just a back-up in case the fish get stressed in the gallon bowls.
How badly stressed is the platy? Will it be ok in the bowl for another night say? You see, idealy, you need to let the 10 dry out completely before re-filling it and adding the other filter etc so, unless your fish will survive the wait, it may be better to just put it right into the 40 gallon and attempt to treat the worms in there (just for the platy).
As for the time it will take, sorry, I realy don't know. I'm assuming you mean the tank you will strip down and dry out (if the platy/other fish don't get moved in first), in which case, after having left it in the sun a few days to dry out and having rinsed out with the bleach etc, I would think they'd be dead - but you never know. If you were reffering to how long it would take for treatment to irradicate the worms, it depends on the med. mostly so I can't help there.
How badly stressed is the platy? Will it be ok in the bowl for another night say? You see, idealy, you need to let the 10 dry out completely before re-filling it and adding the other filter etc so, unless your fish will survive the wait, it may be better to just put it right into the 40 gallon and attempt to treat the worms in there (just for the platy).
As for the time it will take, sorry, I realy don't know. I'm assuming you mean the tank you will strip down and dry out (if the platy/other fish don't get moved in first), in which case, after having left it in the sun a few days to dry out and having rinsed out with the bleach etc, I would think they'd be dead - but you never know. If you were reffering to how long it would take for treatment to irradicate the worms, it depends on the med. mostly so I can't help there.