sorry, i don't know how to get the link from the lemmy.blahaj.zone instance correctly, because it's marked NSFW 😅 but there was a post recently about pumping, and the sub doesn't move too fast, you can probably find it like 3-4 down from this one!

anyways, in there, it talks about traditional air pumping. in the thread, i expressed my skepticism about pumping, due to it mostly pulling in edema into the phallus, rather than blood. however, if you could compress the phallus, so that edema was being blocked while blood was being pulled in, i think has some potential as a growth methodology. and then it was suggested to me that pumping with water (like with a bathmate) might be more effective (in general); which i thought might have the effect of preventing the edema buildup. i've been trying it for a few days, and i like the results better than when i air pump. my erection feels a lot harder and less... squishy? than with air pumping (although this might be due to pumping while standing / in the shower, rather than laying down in bed, idk)

if you want to try this, you won't be able to use a traditional gauge pump, but something like these silicone cupping devices should work: https://www.amazon.com/dp/B09V5149BD?ref=ppx_yo2ov_dt_b_fed_asin_title and they're pretty cheap, to boot

as an aside, you can also try doing more of an active cyclical pumping, where you pump to full, and then release, and then pump to full again, and so on, instead of just holding the pump on your dick. it's a little harder with the cups, but plenty doable. you can try this with air pumping too, it might give you better results, but i still had pretty much the same issues with edema when i tried it

if you try either of these methods, please post your experiences with them! unfortunately this is an unexplored science, so the more experiences we have to work with, the better