OP just blaze outside or in a well ventilated area indoors-use spoofs and try to set up a box fan in a window facing outward and exhale the smoke into that, or if the bathroom has an exhaust fan in it just exhale the smoke into that.
Smoke out of one hitters, pipes, or even a bong. Joints and blunts while fun to smoke in a group of people can produce excess smoke.
I had friends who would blaze in cars and yeah that can be risky and begging to get caught but they'd use small bowls or a small bubbler, roll the windows down, and exhale into a spoof or a soda bottle that has holes cut or burned into it that's filled with dryer sheets and they did this while driving and not on a main road.
If you or your friends have a vaporizer try using that. I only vape now and there's pretty much no smell at all from the vapor like there is with smoking.
Don't carry anything on you, and shimazu offered excellent advice that works too.
I used to do things like wash my hands but IME you don't really reek that bad unless you're hotboxing in a car or indoors but the cologne, being around people who smoke cigarettes or cigars, and taking off your shirt helps with that. I wear contacts so if someone would have asked me about my red eyes when I was into smoking I just would have said I had dry contact lenses. That never happened but I know other people who just said they had allergies.
I used to love smoking and then taking OC but IME it does increase the opiate high and the high from THC when combined. I didn't get paranoid on this combo but everyone's different. I don't think I'd want to go on rides if I was on opiates and nodding heavily and feeling like I was going to puke like you do while on opiates but everyone's different. I remember that oxy would make me hyper and I'd want to do cardiovascular exercise while on it and I had fun playing soccer and just kicking a soccer ball around with friends, running around, and even swimming while on oxy. Then later when I was tired from exercising and relaxing with the nod I'd just chill.
I've never taken any sort of benzo recreationally but aren't those used for anxiety instead of opiates? If you have benzos and opiates don't combine them.
Keep in mind that nobody's going to know that you're stoned unless you tell them. When I was into smoking my friends and I would be blazed as fuck in publc places like classes, where we had to appear completely sober and everything worked out fine.