I would like to know if boiling my tap water would clean it for my iguanas
If you only want to get chlorine out of the water, it is enough to to add the water to a bucket and leave it there for 24 hours. The chlorine will evaporate "willingly".
Boiling is very likely to accelerate the process, while killing some micro-organisms in the process.
While chlorine is fairly easy to remove from the tap water, there might be other substances in the water which might not be easy to remove, and still be harmful for the iguana. If at all possible, have a sample of tap water tested at a local laboratory, to understand what you are dealing with. Depending on the results, better advice can be formulated.
Obvious caution note: be sure to let the water cool, before mixing it with the iguana :)