I'll have to take a look and see if they're available where I am. I use a dry herb vaporizer sometimes but find I actually use more. To be honest I don't pack the bong bowls usually. I do 5 smaller ones. Hold it in until nothing comes out. See all these videos online of people doing massive hits but blowing all the smoke straight out instantly. Hold that shit in. Ha ha. Such a waste.For the most part I have retired my bong and bowl in favor of the @PerfectPipe , When used correctly it produces a flavor half way between smoking and vaping, is easier on the lungs, and it will make your jaw drop on how much less weed you use. It easily pays for itself in no time. OK, i'm not "paying" for weed, but you get the drift. With the size and filter, for cigarette smokers, using it comes very natural. Get just enough flame on it to get it started then get the flame out of the mix. If you need to re-spark it for the next hit, repeat the process. I bet I use a quarter of the bud I used to. I keep trying to migrate my sons friends that want to come over and pack ping pong ball sized bowls. I might just have to make it a rule. Perfect Pipe or you're smoking your own. I hate seeing quality weed wasted.
PS - This was not a paid endorsement. I won my pipe via POTM but have since bought refills and have sent a pipe set as a gift. The recipient of the gift likes it too.