Besides:
You are not going to take a bath in the stuff!
At most, you will have a few CC's out in the open, or a few eyedroppers' full.
Per directions.. you are going to spread a VERY thin "emulsion" of the alcohol/solvent
compound over the surface of the PC board stock, then a bit more on the paper
backing once the transfer and the PC board are in contact.
Very few of us (I would hazard a guess) make large numbers of PC boards that
are larger then about 50 square inches. That might be a 4 inch X 5 inch
board, or some similar aspect ratio.
If you a doing stuff much/more/larger than that, you probably should
start using one of the many Asian PC board fab houses that
do good work, and have relatively short turn-around times.
As mentioned before...........even boiling water can be very harmful.
Regards.
Roland F. Harriston, P.D.