For the husband:
Concept: She gets taken to the very beginning of an orgasm except instead of cumming, electricity applied to her clit vaporizes the orgasms. Not just makes them not happen but leaving her with with every bit of desperation and the feeling of having her orgasm totally ripped from her. She will very much feel like a victim with each and every kill. You absolutely need an O-ring gag if you plan on being orally serviced during this. ABSOLUTELY!
You can play this hardcore where she gets zero orgasms, or you can allow her a one in six chance to cum. Let's assume hardcore. PM me if you want the other instructions.
She gets tied down spread-eagle to a bed or table, etc. Nice and very spread. Tie her knees as wide and flat as you can. Make her pussy spread as much as possible. Put a thick pillow under her back to force her to arch upwards. And a pillow under her head too. She'll be gagged unless you decide to muffle her screams by allowing her to scream into your cock. (I've been told that the female recipients of said screams will often cum from the vibrations of the screaming. Remember, the more intense the orgasm, the more painful/devastating the kill when electricity is applied to the clit.)
Now you use a Hitachi Magic Wand or similar to masturbate her to the most amazing orgasms you can. Your other weapon is either a violet wand or a battery-powered electric bug zapper/fly swatter (very common item). Either will deliver just enough electricity to rip her orgasms to shreds. You can be sure that she'll be begging and crying, cursing you (and me) and promising you anything to just stop the torture.
Maybe you want to occasionally apply some nice soothing ice to her pussy. I'm sure she'd love the change of pace. Same for her nipples too. Use some chopstick clamps on her nipples too so you can twist and pull them while you have her service you. Great for encouraging her to a higher standard of performance.
For extra fun, if it's just the two of you, definitely get video so you both can relive the experience while you cradle her in your arms. Of course she should be bound but it's a great time for intimacy. If you want, blindfold her during the original session.
Another option is to invite some close friends over to also enjoy this dynamic experience. She may already be bound and blindfolded when the doorbell starts to ring. Mindfucks are always so much fun!
Almost forgot. How many kills? START with 100. I've had subs exceed 150 in a single multi-hour session. A lot depends upon how powerful you force her orgasms to be when you kill them. If she tries to suppress her orgasms so they won't hurt so much, some shocks to her inner thighs, or vigorous rubber band snaps directly to her anus will gain her renewed efforts quickly. (BTW, don't leave the nipple clamps on too long for safety reasons.)