For 'soaking' the self-adhesives (peel and stick) type of stamps out now, use white spirits cautiously and a steel rule to scrape the gum residue off. It goes by different names in different countries. Wal-Mart or hardware store.
There is a video on U-Tube (don't even know how to spell it, don't use it much) by a fellow in New Zealand that is good, showing how to do it.
Search on SCF here for soak or float in the title only and lots of discussions will come up.
Depending on which country you are soaking, water can still be used.
The drying book called Desert Magic is the best book to use. It has opposite pages of non stickable stuff so even stamps with a bit of gum still on will not stick. Check
ebay or your current stamp source. Other books do not work very well.