Yep. Rubbing alcohol is 30% or more water.

Isporopyl 91% is . . . 9% water.

Solvent alcohol and stove alcohol are similar; in the 90% range.

"A drop or two" won't make much difference. I use about 30% solvent alcohol with 30 minute epoxy when fuelproofing firewalls. That's just to fill the wood and NOT as a fastener cement.

Always mix the epoxy first and let it set to cross-link, then add whatever - fillers, thinners, thixotropic additives, etc. You can thin epoxy with acetone, also. It adheres, but you're tempting the fates as far as the final overall strength. If you need it thinner you can warm it up in a bath of dishwater temp. hot water. But, the cure time will be much shorter.