Re: more seriously
About 15 years ago I had a go at this and made a couple of controllers based on a DTFM decoder and a PIC, and hacked some Ann Summers devices to make male and female versions. All they needed was a phone at each end (even a land-line phone would do) to control them without any data collection happening in the middle.
Quite fun, but back when feature phones were still the norm (the iPhone was still a couple of years in the future back then), trying to remember which numeric keypad button corresponded to a particular fun-toy function (and, yes, they could do way more than the standard Ann Summers toys they were based on) was hard when your brain wasn't entirely in your head.