I haven't tried to get high on nutmeg, but from what I've read, it's fairly unpleasant and lasts much too long. Three tablespoons could be fairly unsafe as well. I'd choose diphenhydramine (benadryl) or DXM over nutmeg. I have a bit of experience with diphenhydramine and it sounds slightly similar (I would suggest staying under 250mg). DXM is the most recreational of the three, although I wouldn't take more than 400mg. At least start with less than three tablespoons. Also, I've read that high doses may cause organ damage, but that's not uncommon when you take high doses of any of those three. Have fun.
p.s. 450mg of DXM gave me significant but temporary after-effects, and 1g of dramamine (similar to 500-600mg of diphen) has given me effects that have never fully disappeared, although they are normally subtle and infrequent. As with most or all of the people here, I'd recommend against it.
If nutmeg is just too unpleasant, damaging, or long-lasting for your taste, diphenhydramine+weed will produce a decent trip-like high. Start with a low dose and try different strains of weed. I wouldn't exceed 150-200mg of diphenhydramine, and would start with 50-100mg. Combined with indica-dominant strains, it may make you very sleepy, but combined with sativa, it could make you fairly paranoid, so I'd prefer a strain that's roughly 50/50 indica/sativa.
I haven't done this many times, but once when I expected to see faint diphen spiders on the wall, I saw many tiny, coloured nearly-nude women (they weren't moving much, just arranged in neat ways). Weed makes diphen visuals seem less realistic and slightly fake but also interesting and impressively hallucinogenic for such an easy combo. On the same trip, I looked into the reflection of the TV and saw a bunch of people, interacting and moving (they were just objects in the relatively dim room). I also had the impression that I was travelling in a bubble, over people who looked at me mysteriously yet in a friendly way. Unfortunately I couldn't interact with them, and this made me a bit sad. It was slightly comparable to being at a trance concert while people on E observed me and I observed them, but without much communication between the two realities.
Taking too much benadryl is very unpleasant, as is the hangover.
Back to nutmeg though.