OOPS. I meant to seperate those two words with 'or'. I probably shouldn't even have used the word 'sap' either, but so many people use the words interchangably, I assumed they would relate it to what I was explaining. I also realized after reading your post, my inappropiate use of the word 'callous' where I should have used 'callus'. I have edited my last post and cleaned it up a little, although I know of one prominant North American bulb propagater/grower that uses/spells it (callous). I prefer to use 'callus'.
I think we're going to see quite a bit of slightly differing procedures from one individual to another or even from one company to another when it comes to cloning.. The one I referred to above uses milled sphagum peat moss straight in their scaling process whereas you and I like to think we go one step better and prefer to use milled raw sphagnum moss. So, it's not uncommon for differences to 'pop up' from one to another. In the end, they all work. Scales are pretty good at producing bublets regardless; I've even had scales I discarded and threw in a cardboard box, which I discovered weeks later, had formed bublets in open air. But that doesn't stop people like you and I and your acquaintance from striving for excellance as our curious minds directs us to. And only through an open discussion of our procedures coupled with an exchange of our results as they present themselves will we become even more knowledgable.
A short story about me and 'the callus': During my scaling early on, I inadvertently observed that scales tossed randomly on my Kim-Wipes, those with the cut facing up develpoed a nice callus over night and those facing down in contact with the Kim-Wipe did not appear to have developed a good visable callus. Looking closer, I saw this little stain on the Kim-Wipes wherever the cuts had made contact. Allowing them to dry further still did not appear to produce a good seal like the others where the cut was facing upward. I deducted that the weep had been absorbed by the towel and its loss resulted in the inferior callus. From then on, I've always made it a practice to place the scales with cut side up, canoe style. I don't know if it means anything but I've never experienced a spoiled scale since.
