I use it two ways:

I develop the film rated at ISO 50 in Rodinal 1+50 for 10-12 minutes with 1 minute agitation at the beginning. Then 5 sec. (2-3 inversions) every 30 sec.
Gives me wonderful tones.

I rate it at ISO 25 and develop in Rodinal 1+100 for 13-20 minutes depending on the contrast I want. Mostly I develop it for 16 minutes.
Gives me great control over contrast. I use this with studio shots only.

Have a gooooood Rodinal Time.

Greetings, Morten (Rodinalution will come!)