I'm a little cautious about saying this, cause I recognize my experiences shouldn't be assumed to be reflective of everybodies, so, I'll just preface this by saying maybe I'm talking out of my ass here.
But... That really sounds needlessly reckless.
I get it, at least partly, when I was using heroin homeless every day I took a million risks and didn't really worry about it. But cigarette butts off the street?
Cigarette filters are shitty filters even from a junkie standpoint, since they seem to stay noticeably wet even after you draw up. And cotton is so cheap and widely available. I just can't see why you'd ever "need" to use discarded cigarettes as a filter.
I can see giving so little of a shit that you take stupid risks, I used to do that too, but again, cigarette filters are shitty.
It sounds like intentional self destruction.
We (me and my BF at the time) used to reuse needles probably a hundred times because we just weren't willing to take the time to get more. But we'd still get new ones on occasion.
I get not using micron filters, I never used them either and I'd agree in many more severe addictions it's probably not very realistic. But even we could get cotton, it is available all over the place, costs almost nothing (assuming you don't just steal it) and you need so little of it per shot.
I dunno, I'm not looking to judge you man, maybe I'm missing something here. It just sounds needlessly self destructive. I know this lifestyle involves taking a lot of risks, but they will eventually catch up with you so even tiny things to make it a little safer can make a difference.
Maybe your circumstances were different to mine, but it sounds more like apathetic self destruction to me. Again that's not intended as a judgement, I used to refilter shots to remove my own coagulated blood to then retry shooting them cause I'd missed after registering, I know addiction can make you do suicidally dangerous things.