Cock rings, do they help?

Short answer: Yes. Stretchy silicone or leather cinch strap "Constriction Bands" will help maintain an erection.

Constriction bands are briefly worn by guys for either vaginal or anal copulation. Check with your Urologist for a recommended maximum time to keep the band tight so as to avoid permanent injury to your penis. Most likely not what you want for an Aneros session though since our more sensual experiences are not focused on the penis and we cycle back and forth between flaccid and erect during a session. and back to flaccid many. That cycling is a healthy thing since it refreshes the blood in the Cavernosa.

On the other hand, steel or aluminum cock rings are worn by a number of us sometimes as 'jewelry" or to provide a strong sense of masculinity during a session. My wife likes to see me "wearing my jewelry" and seems to regard that decor as a symbol of dominance. Mine are engraved with the same words that are inside my wedding ring.

Sizing of metal rings is critical. There's a good explanation of Cockring fitting on the Gear Essentials website.

HTH... rook