Question
The top and bottom of my tortoise's shell tend to get messy from wet substrate, waste, etc. How can I safely clean the shell, without damaging it in any way?
Answer
I was afraid of damaging the shell (particularly in the growth regions) by scrubbing at it, so the tortoise's vet recommended using something like baby shampoo.
Baby shampoo has had some unfavorable press in the last few years due to additives. However, most of these additives have been removed from the formulations, and it also uses mild surfactants instead of soap. Surfactants are safer than soap to use in the growth regions in between the scutes (plates) of the shell, because these regions can dry out with regular soap, causing cracking and disturbing the natural "growth rings".
Using a soft cloth or chamois to gently wipe the surface and rinsing the tortoise well to get rid of any residue will remove most of the surface dirt.
Answered By - jonsca