For inspections i don't use anything while i'm going through the hive (i've got a TBH) when i'm ready to close up i use a spray bottle of water (with a little cider vinegar), they think it's raining and quickly shift back down between the combs so i don't crush any.
I've not used a smoker yet (don't actually own one), but with the top bar, inspection isn't as intrusive.
I use a water spray to coax them back down between the combs though, so they don't get squished by the bars