Chastity and orgasm denial discussion

Greetings everyone, I picked up some solid tips and viewpoints in the other discussion regarding short-term chastity, so I wanted to bring another question here: what methods can a keyholder use to reduce an erection when reapplying the device? My partner hopes she can remove it, tease me, provide her services, and then replace it without letting me finish. The issue is that fitting it back on while I’m erect seems impossible. It would be more thrilling for her if she could apply the cage herself or watch me do it in front of her, but the mix of mental arousal and physical stimulation makes it very hard to get my penis to go soft again. Does anyone know any good methods their keyholders use to calm an erection so they can reapply the device on their own? Cheers!