You can use bar soap. But not just any. It still needs to be reside free, and work well in whatever water type you have. Since you're in the UK, I'll bet you have hard water. Most of the UK has it. In that case, if you use baking soda, you'd have to boil the water first, and try to purify it as much as you can. It's possible, but takes some time.
With the bar, or liquid soap, you do the same thing. Just scrub your scalp. Lather it up nicely. scrub gently with your fingertips, and rinse it out really really well. As it rinses out, it'll wash through your hair, cleaning it.
www.dreadlockshampoo.com is awesome or the baking soda method found ion here yea aur dry
Welcome. If you aren't using soap, use it. Get a good non-residue soap, and wash 2-3 times a week. And like Eagle said, don't bother with a towel. It will undo the knots you want to form
welcome you really should wash with more then water..an d not use a towel