Or does that defeat the purpose?
I want to start using wheel filters but they are 4 to 5 dollars each and I don't think I could afford that! If you could use them say, 10 times each it would be affordable to me,

Also, do you need a special syringe for them or could you pull it up through a regular insulin needle?

Thank you!

It pretty much defeats the purpose, even in four hours enough bacteria grows to cause a dirty hit. So it's adding more shit than it removes.

After using a filter, inside is a closed moist environment . A breeding ground for bacteria is not the smartest place to pass your drugs through.

Myself and friends have reused a filter 4-5 times in a night, but don't put it away and take it out in a few days.