Hi Aldevaux, I agree with you, I should have said that drenching would only work if you have a very well-draining soil mix. If the soil is bad or compacted and don't drain well, then drenching it regularly could really make the problem worse. I have also seen people take compacted and pot-bounded maple trees out of the pot and immerse the root ball in water for 1-2 hours, once a week for a couple of weeks, and also clean out the inside of the pot, in order to leach out the salt. This technique is supposed to be effective but I have never done it so I can't vouch for it.
For hot climate, like in Southern California, keeping the maple bonsai pots on top of a cool gravel tray is also very good too, because as the root tips poke through the drain holes, they won't get blasted by the hot-drying air. Because if the root tips get burned, the leaf tips will scorch too. I just keep most of my bonsais on the ground in a gravel planting bed in the summer. They seem to be alot happier than beeing on the high benches.
BTW, Aldevaux, you really know your chemistry!
Si