I’ve used only vaseline when I’ve pumped. It plumps up just fine, and I doubt a water-based lube would do any better.
The big downside to vaseline is that it stays on your skin for at least a few days, even with a good scrubbing. I have a fear of some casual blowjob presenting itself to me, and having vaseline residue on my cock. It happened once already to me, after a one hour shower, and the girl still knew something was up.
Luckily she was a little desperate, and didn’t make a big thing about it.
VASELINE USERS BEWARE!
I'm consistent in spurts, but gains are undeniable!
2007: BPEL 5.5" / MSEG 4.7" / BG 5.5"
2017: BPEL 6.8" / MSEG 5.3" / BG 6"