Alcohol does leave behind residue .... 90% alcohol means 10% something else ..... it's very good, but it's not the best. I used to use 99% alcohol which ran me about $16 a bottle (90% is only $2.50) and was gone quickly as other peeps in the house would use for other things ..... three teenage boys scared on acne for example
.... car dashboards, computer screens, KBs and mice ....etc
Indigo Extreme Cleaner is half the price for just a an ounce or so but it sits in my toolbox and nobody touches it
..... I apply with foam Q-Tips covered in cheesecloth but so far the ounce is about 1/3 gone thru about 11 blocks / HSs so far....that's 6 CPUs and 4 GPUs and a MoBo Block. And on the GPUs include the VRM, VRAM etc