Spreader bars and blindfolds are great for solo play. They can be put on easily and taken off solo, but restrict movement and the vision enough to give a feeling of being restrained and controlled. I’d say they’d be fun additions to your nipple clamps, for sure.
I remembered a thread on the topic of reluctant OH’s from last summer, which you might find interesting. I’ve quoted below (hope I’ve done this right).
Of course he doesn’t have to want to do anything he’s uncomfortable with. I just think it’s interesting to consider whether he may have the wrong end of the stick where it comes to peoples motivations for BDSM desires. It’s not about who we are in everyday life. It’s play. It’s fantasy. There’s irony. It’s not about wanting to be actually abused, controlled or hurt beyond what’s fun.