We already know that Diphenhydramine bodyload is among the highest of all drugs, even more recreationally, but I used to do Diph 3 nights per week 4 years ago and now, that I have experience with amounts of LSD, 2C-E, DXM, K, lots and lots and lots of benzos and opiates, etc. I can say that the 'trip' that Diphenhydramine creates its UNIQUE. I think it Really deserves a try, at least one or two times per year. Belladonna alkaloids.... gotta have to love the fear and despair... also, the music appreciation on large doses of Diphenhydramine (350mg~) its UNIQUE too. No other drug can make you hear the "sound channels behind" a song.
As long as nobody goes beyond 400mg I think this drug can be taken recreationally sometimes without problem. As long you know what youre taking and what you will feel... I think its all right.