I am going to be switching cases soon, and I thought it would be wise to take the time to clean off and reapply the TIM to my CPU cooler along the way (didn't do a good job the first time around so have been meaning to do that for a while now) . This would be my first time doing this, and I do have coffee filters available, but I am noticing that noone seems to be selling 99% Isopropyl alcohol around here, it's all 70% and 91% if not lower. I've heard that you can still clean thermal paste off with lower concentration solutions, but a lot of these are from fairly old sources so I was just wondering if it was still true. I am also changing out from my badly applied Thermalright Chill Factor that came with my cooler to the MX-2 I have lying around, so I was wondering if that might change anything. I'm pretty sure it wouldn't, but I have also heard that some pastes like AS5 leave a residual amount on IHS crevices if cleaned that might affect performance of the new paste.