I know of some bjj places that do every once in awhile, and I want to know if judo places are similar (with judo rules I assume)
South Hills judo club on many Saturdays does.
If you are in the Dallas area - Dallas Judo club. Saturdays from noon-whenever - bjj, judo, sub wrestling, whatever...
if you are in the Oklahoma City area - USA Stars Foundation. Moore, OK.
Coach Burris hosts them every couple of months.
Having traveled some, and having visited a few dojos.......I would say that some dojos will make you sign waiver, some possibly pay a mat fee and you can train one or two times.
If you travel, you're better off asking your instructor to suggest a place and maybe make a phone call to the dojo instructor out of courtesy. Similar to the Japanese formal introduction and BJJ intros to the dojo that you're visiting.
Your instructor will do things like introduce you and vouch that you aren't out to hurt anyone and gain a reputation.....
If I remember, you train in bjj. If you're training in Judo now, ask your instructor to make a suggestion.
If you're wondering because you are thinking of taking up judo full time, then call ahead and ask if you can do a couple of trial classes. You were asking about Tohkon in a dif string. Great place to train.
Judo clubs also have legitimate insurance, so they have to be a bit more careful...
South Hills is in Pittsburgh.