Just wondering, if user bother to provide evidence they use ChipMixer (or other mixer),
Tracing back an input if I find an address has 0.xxx bitcoin then it could consider that it came from chipmixer since their minimum amount is 0.001 BTC with 0.001 BTC increments. But a single bitcoin user can create the same cheap and then spend it which will look like they are coming from chipmixer. Ideally, there are no valid way which will find out 100% that it came from Chipmixer.
Off - topic: Has anything wrong with ChipMixer clearnet?
Due to recent events ChipMixer is available only on Tor network.