Here in NY as a cannabis user, one of the brands available that offers vapes (Fernway) offers a recycling program at dispensaries. I get 10% back off my next vape/cart if I return the old one to the recycling dropbox. My dispensary also keeps how many I've returned on file if I return extras, so I keep a 'balance' of disposables returned for the discounts.
And you also need to refrain from breaking this scheme entirely, by introducing silly restrictions like only exchanging for in-store vouchers instead of cash, or demanding same-store receipt for original purchase (or equivalent) - like it happened in some places (e.g. my country, Poland) to glass and aluminum recycling.
Such restrictions seem to purposefully target poor people, and I have rather strong ethical objections to them (something about making a problem invisible and hoping it'll go away - or starve out), but the effect goes beyond that. Getting $20 back on a $200 product would be a different story, but here, it's more like $2 on $20, or $0.2 on $2; most people aren't going to bother with that (and understandably so: it's not worth the logistics overhead). So at best, all this does is redirect money stream from poor people to recycling companies. More typically, it just makes people recycle less.
You need to offer an incentive (ie: discount on new vape if you recycle) and then, from my experience, most people will recycle.