If you use it according to directions you'll be fine.

But if you have concerns... take a paper towel and give the snake a wipe from chin to vent... that should clear up any doubt.

And mite feces is ashy colored, so you should be able to see it on him.

I hate to say it, OK, I love to say it... but PS is the absolute worst in IMHO.

But hey, you have a snake that you'll enjoy for the next few decades, so it is ALL GOOD! And the snake has an attentive keepers.. so even better!

Good luck with him,
Bruce