Josh just isn't messing with drugs much at all and he's a bunch of talk for the most part. I don't doubt he's dabbled but far less than he even brags. His explanations of any psychedelic drug is as sitcom cliche as his outlook of gender relations. "Ooh colors". He is just parroting a bunch of nonsense.
He sticks to alcohol, cannabis/cannabis variants (Delta 8, CBD), caffeine, nicotine, and kratom. Plus his junk food and porn addiction. He blows so much of his money right away on these things, he just can't keep a harder habit.
The dude would have been seriously tempting death if he was hopped on benzos with the way he drinks, he'd be absolutely blacked out far quicker and harder. For all his talk about cocaine, I even doubt that. He watched some Ozzy YouTube documentary type videos and he was sperging out about Hunter Biden around the same time he started to bring that up again. He has the teenage mentality that rock stars just get wasted and that is what makes them cool. He's about the image.
So I doubt he's ever had a psychedelic experience, decent coke is expensive/hard to come by/requires a modicum of social interaction, he would have had a lot more close calls with death if benzos, he demonizes prescription stims because he was forced to take them by Clint, even the whippets that have been sitting on top of his microwave have gone unused all year, I assume a fan sent it and he has no idea how to use them or is scared off by it.
I think if he's getting pills at Walt & Angie's, it's far less than people think and a big reason, besides Ellen, that he goes over there is that he's incredibly lonely and it's a safe space for the most part. He knows the trolls can call them but they put up with it, he can control the situation and fulfill some social need and feel wanted without the baggage of his drama-filled friends like Warlord or Scotty. All his old friends don't want to hang out with him or have moved on and his anxiety is high despite all the big talk.
I know he said he's done muscle relaxers, who knows what that means to boglim brain though. I think if Walt's selling Josh pills, it's tramadol from the VA and it's happening far less than people want to assume he's drugged up. I think people are looking for some excitement to speculate on when he's just a huge alcoholic. People weren't around for the scooby snack/spice saga which was always super obvious when he was on it.