I've been following Don Cardwell's advice on the apug forum, of five-minute agitation intervals using Rodinal (Adonal) at 1+50 and Tri-X at 400, and it works perfectly for me. Even the agitation every five minutes is minimal - just two very gentle and slow inversions. 25 minutes at 20C (yes, 25!) The following is an example. It’s a scan of a print, and it’s not the best scan I'm afraid - the print is sharper - but it gives a good idea of the tonal qualities produced by the method.
Anthony