Keeping the pump up is good and advices here are solid.
I've used the ROP for my post workouts. I usually don't wear it too much, as in not to spike some weird imbalance in testosterone and so on.
For post work out I usually apply some cream or oil, like leech oil. Coconut oil could do fine, as long as the cock ring can withstand oil. Essential Vein Oil is one thing a guy could use after a session, albeit it needs to be made, but it's good stuff and depending on the source, not so expensive as leech oil. And I know some people wouldn't want to use leech oil anyway.
So, Essential Vein Oil would be my add to having the cock ring on, as long as the rings material can deal with oil. Honestly, I've broken quite the few rings because of unsuitable lubricant. Silicone in my own opinion would probably be the safest bet as already mentioned. TPR, especially cheaper TPR rings, will break easily. Oxballs TPR line has lasted the longest for me, they have some good designs.
I'd look for a decent width in a cock ring, for me that's a lot more comfortable than any O-ring type. O-rings can be great for workouts, but for post healing they are often too restrictive. And the way they can groove into the skin, it is not such a pleasant feeling. So, me repeating what others have already stated, a snug fit for post workout, not the super-tight ring that makes your veins bulge like crazy. Those are for other times.
maintian a pressure storng enough to stay erect weak enough to cause no fluid buildup
