In my opinion advertising those as suitable for "your aquatic friend" should be a criminal offense. I'm with @Colin_T on this. 10G plastic containers cost a few pounds. Just add a heater and sponge filter. In the UK that would cost me 10 - 15 pounds in total.
I just leave my sponge filter in my main tank (in addition to its own filter) when my QT is not in use. Then when I need a QT I just move it across and have an instantly cycled tank (ok its really a tub).
Hmm.... well here in Canada a new heater is at least $40, bucket is probably $10-20, I found a sponge filter on amazon for $6 but it needs tubing and an air pump, and here an air pump is $20-50+, or if I just got a filter its at least $30. So I was hoping for a non cruel to fish short cut. Otherwise I will just use my 10 gallon tank for quarantine and take all the fry out.
Hmmm - buckets don't need to be anything fancy. Mine came from the local hardware store and were sold as storage bins - the pound shops do them too. They are not see through. I had to cut the lid cos its sort of like a massive school lunchbox with a lid. Filters with air pumps are pretty cheap on amazon if you get the Chinese unbranded ones (as long as your tank is going somewhere where you won't be bothered by the noise).