Sizzle is good - when they are new and vaporzing their best you hear sizzling
Don't count on cleaning them. Some people are successful and some are not. You may be successful or not. In any case, buy enough blanks to not run out. If you resurrect some well-used ones then that is a gift.
My juices have to earn cartomizers. Only juices I like enough to vape for weeks get cartos.
What kind of carto are you using? I use Boge 510 standard resistance (since the LR has the potential to damage slim batteries). I love the Boges. I usually alternate
vaping a pair of them and and can often get 2-3 weeks use out of each that way.
I find thinner juices seem to make the carto last longer. I am now going to buy 80pg/20vg more often because some of my 70pg/30vg juices are thicker and seem to make the carto more sluggish at vaporizing and dragging. I use a thin clear
juice from Vapor4Life (WOWbacco) and the carto looks like new for many refills.