My physician team almost always keeps the catheter in for three weeks.
(I suspect it keeps the patients from getting too active....)
I had mine in for 21 days, also. I also had very little control upon catheter removal - while standing - for some time.
Your husband has control while sitting. THIS IS GOOD NEWS!
The unconsciously controlled (smooth muscle) valve of the bladder is still working.
Your husband needs to walk a lot (with liner pads) and be patient as the stretched bladder and shortened urethra both get accustomed to their new positions. For now, try holding ever-increasing amounts of urine in the bladder as you are sitting.
Kegel exercises: Your husband should be doing at least three 20 to 30 minute sets a day.
After a few weeks and the muscles get stronger, he can do more. As many as he feels like without getting exhausted.
It takes awhile to develop the necessary muscle tone of the pelvic floor muscles.
This flexing - supports and works with - the remaining bladder valve.
Tamu's suggestion about contracting the muscles to stop the stream flow is good.
In Bluebird's Journey (Lee & Buddy's Journey), Buddy starts and stops the flow over the toilet.
He practices kegel exercises on the stairmaster. This is good as walking stairs without leaking is one of the early challenges in gaining control.
If after week 8, you don't see at least some improvement in control while walking, I agree with KW that you will likely benefit from working with a bio-feedback therapist that will make certain you are exercising all of the pelvic floor muscles. I talk a lot about my work with my bio-feedback therapist in my thread "Zen and the Art of Symphonic Continence"
If you have time to look and want some encouragement, this thread is linked in Helpful Links at the top of the page under Other Topics.
I also talk about walking around the garage nude with a styrofoam cup to learn how to flex while walking. Again, all of this is about muscle tone and coordination, not just a constant 24/7 flex.
Don't get discouraged! While a very few have almost instant continence when the catheter is removed, most don't gain almost complete control between months 4 and 6.
I feel a positive attutude will help speed this healing.
Many of us felt we would never really gain control. Then, one day after week 16 and before week 24, most just suddenly don't need pads. It is that sudden.
2 Years of PSA between 4 and 5.5 + Biopsy 23DEC06