Fragrance free retainer/denture cleaning tabs?

Has anyone found a fragrance free retainer/denture cleaning tablet?

They don't list ingredients online. The ones that don't mention scent/fragrance nevertheless have descrete images of mint leaves which is a sure sign of artificial mint scent and/or menthol.

I know ultrasonic cleaners and uv light sterilizers exist. But my friend who uses only those still slowly gets a build up on his retainers.

If I can't eat or go anywhere with smells, I'd at least like a clean retainer. Is that too much to ask for? 😭