Homebrew PCBs

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.