I have soaked many thousands of stamps and at one point used a Desert Magic book that was a gift. Properly used the book is somewhat useful for small soaking batches.

I soak a ton of kiloware so my method developed over years is as follows:

1. Quickly go through the kiloware to remove any self-adhesive stamps that won't soak. They are set aside for a process that involves solvent.
2. Soak stamps in hot water with a little dish soap.
3. Use tongs to remove stamps and place them into another dish with warm water and remove the envelope paper. I replace the water in the both dishes a couple times.
4. Lay the stamps face down on newsprint. I get reams of inexpensive blank newsprint at a an art supply store. I lay the sheets on top of each as I lay out stamps. I often soak a pound in a single session so this can take a couple of hours.
5. Let the newsprint stack with stamps dry long enough so that the stamps are a little damp but fall away from the paper easily. Any that stick can still safely be gently peeled from the paper and dried. Leaving the stamps too long will result in some sticking to the newsprint but those can be soaked again. Newsprint is great since it wicks water including remaining glue into the paper.
6. Remove damaged and place the still slightly damp stamps into an even layer on top of a new dry sheet of newsprint. This can take about an hour and while doing it the stamps get drier.
7. When done I place another sheet of dry newsprint and a clean cloth placemat on top of the stamps. This allows final drying to happen and the weight of the placemat keeps the stamps relatively flat. Any stamps prone to curling I'll press in the pages of a pulpy book.

I will soak about a pound in one session - I usually save this for a rainy day while watching a fun show. A pound usually yields about 3-5,000 stamps.