To ` cover` both posts, and I`m not being picky, or pedantic --just allow me to say that I never ``bother`` with alcohol ``percentages`` --- I just go with what it says on the bottle i.e. Lace-release, Glue Melter and Citrus-based Solvents [for really stubborn residues]
Lace release is exactly as it says---it releases your lace from the underlying glue and/or tape.....you simply spray it onto the lace directly ` above` the bonded-area......allow it time to penetrate down through the lace, and your system will come free easily and cleanly [no residue]. Keeping to a regular de/re and clean-up routine avoids a lot of problems.....if you leave the bonding products on so long that they begin to deteriorate / go ` gooey`, then you`ll have a headache and time-consuming clean-up. I use a dropper too, to ` aim` the alcohol in a more localised fashion rather than spraying it on, as it`s getting onto the actual hairs and has a negative [drying ]effect. When removing the system, just use gentle lifting-pressure---don`t literally tear the thing off....you`ll damage it in some way...if you find a bit which is ` refusing` to lift or is still resisting, just apply a little more lace-release, and it will free it no bother. Then you can work on your residue on the scalp with Glue-melter/ Citrus Solvent [C-22 or De-solv-it] You must allow at least a minute for the lace-release to penetrate/soak through the lace, be patient..work around the perimeter slowly...that way, you should have little if any residue on the system..it should all be on the scalp. Hope that helps!