The following article on Bestine is provided by long-time philatelist Stuart Keeley: “The self-adhesive stamps of some countries cannot be removed through conventional soaking. Indeed, immersing these stamps in water will result in the stamp becoming impossible to remove from the paper. While this list is not comprehensive, the recent adhesive stamps of the U.S.A., Australia, France, Spain and most Great Britain are countries where BESTINE will allow the stamps to be removed. The suggestion is to try with a definitive stamp first to learn how.
Place the stamps in a shallow container face down. Apply just enough BESTINE to the back of the stamp to wet it through (an eye dropper works very well). After a few seconds (10) pick-up the stamp (USA comes off fairly quickly, others take a bit longer) and carefully peal this stamp off the paper. There will be a residue of the adhesive on the back of the stamp to which a bit f baby powder will neutralize the stickiness. (As a side note: coloured paper does not need special treatment when removing those stamps that are affixed to coloured envelopes.)
Self-adhesive Canadian and German stamps (for example) do not require BESTINE to remove.
The traditional lick and stick stamps (and the modern versions) should never be immersed in BESTINE. If they are then the stamp will not come off.”
Peter Butler wrote a column about this in Canadian Stamp News, when he was contributing a column to CSN. Here is a paragraph from that edition of CSN:
“Using Bestine is very simple. You apply it to the backside of the envelope paper, (the inside side!) not the stamp, using the tiniest amount from an eyedropper. You then peel the stamp from the front-side of the paper. All the glue remains on the stamp but it is no longer attached to the envelope. After it dries, the solvent evaporates very quickly, the stamp is dry but a little sticky on the gum side. A gentle rub of the smallest amount of talcum powder or corn starch (inert substances to be sure!) solves that problem and the stamp is ready to put in your album – no remaining odour and no stickiness – ready to accept a hinge.”
Also from 2009 (INCLUDES A VIDEO CLIP):