Yep. I built 6 grinder timers in 2007 for the 2008 Barista Championship season. Some ended up being sold, 2 were cannibalised and fitted to David Makins BNZ conicals for the 2008 World Barista Championship. All you need is a timer, a project box, a momentary SPST switch, some wire and some wiring capabilities - although I suggest you get a sparky to do it. Most of these timers have inbuilt relays so no need for a SSR. Just make sure that youre not pulling more current than what the inbuilt relays are rated for, otherwise you will need to use a SSR. That said these timers were used successfully on big conicals (Compak K10 WBC, BNZ conical).
These timer boxes require no modification to the grinder if the grinder has a straight on/off switch (like the WBC/Pro Barista conical from Compak). Otherwise grinders will need to be rewired to just have a straight on/off switch. Then you simply plug the grinder in to the back of the box and power is supplied by an IEC power cord (computer power supply cord).
As for the rocky, you will find plenty of sites which detail how to bypass the spring loaded switch.
Im not going to detail step by step how its done because I dont want you to die if you screw up.