I don't really use any products in my hair besides moisturizers and natural oils for sealing, so my *current* plan is to only shampoo once every 4-6 weeks or so. Since I've been wearing my hair out (as opposed to under a weave), I've been co-washing every other day.
I tea rinse and co-wash twice a week, and use a non-sulfate poo once every two weeks. My hair hates daily cowashing and too much moisture, so I can only cowash after a tea rinse. Twice a week is a good balance.
I shampoo once a week or every other week. And then I cowash once a week or every other week. I rotate between the two. Now since it's so hot and humid I find I have to wash once a week and cowash in the middle of the week. So it's been twice a week concerning that I suppose...?
Once every two weeks. Its only been about a month (or four weeks or two washes) since I've done this. I have found that it has helped a lot with cutting down with manipulation (with the addition of wearing twists). I will continue to wash my hair on this schedule until my hair shows that I need to try something else. However I will begin to rinse my hair with just water a few times a week; reason being that I just started with MT and don't want protein overload to occur.
With shampoo only like every 1-2 weeks... I've never gone 3 weeks b/c at that point my scalp would have so much build up it would be itching something awful....
I cowash pretty much daily... as frequently as twice a day or as infrequent as every other day.
At least once a day my hair gets drenched in water, even if I don't do anything but rinse.