Do poppers show up in a drug test?
It's very unlikely. Poppers are usually isobutyl nitrite/butyl nitrite/amyl nitrite - not chemicals that are detected by standard drug tests that focus on things like amphetamines, cocaine, opiates, cannabis...
If they were searching for metabolites of the specific substances mentioned above, they would find them - but that would need to be one hell of a specific drug test that would likely cost a lot of money, so have no fear.
Poppers are lovely to use during sex they say. Loosening muscles around the arteries causes blood to pump faster from the heart, resulting in a rush to the brain. The vaginal and anal muscles become relaxed too. What a blast!
Does rush show up in a drug test?
You mean the "rush bath salts" that are sniffed for a good time? The active ingredient here is MDPV and, again, can be detected if being searched for specifically - but most standard drug testing does not factor it into the equation - so you should be safe here my friend. Bare in mind this substance will soon be made illegal by the way, much the same as they have done with K2/Spice :(