Keeping tzitzits clean, especially those worn on a daily basis, can be quite a challenge. I just came across a string of posts on the topic, with a wealth of original tips, including both do’s and don’ts.
This was my personal favorite:
I gave my tzitzis to a laundry place to wash. When I came to pick it up they charged me £35 and when they saw my look of disbelief as I examined the receipt they told me, “Yeah, it was hard work undoing all those knots!!!”
Apparently the writer was unfamiliar with the halacha on this subject (see Rema, O.C. 21, 3 and M.B. 16).
Link: Cleaning Tzitzits>>>