360 hydraulic lifter failure

It's been a few years since I tinkered with hydraulic flat tappet cams. The last time I bought a set of hydraulic lifters was about the time the chineseum parts were filtering into the states. I took all of the lifers apart and soaked them in acetone. Once I took them out, I strained the acetone through a white coffee filter and was surprised at the amount of trash that was left in the filter. I don'[t have a one size fits all answer, I just know that Chinese parts are "going" to fail no matter how good the look.