Could a cop physically restrain a 10 year old? Yes.
Is that "safer" and less "traumatic" than a taser bolt? Good question.
Restraint holds can hurt. A lot. That's the point of them, they make you want to stop whatever you are doing and for the pain to go away. They also have to be kept on and there is the risk of tendon damage, dislocation, breakage and even death*. Is that risk lower than a taser bolt? I dunno, I'm no expert and neither are you Dunning-Kruger fools.
The preferable action (maybe) would have been to have the child removed by social services. If she has enough mental problems to throw a violent wobbly when asked to take a shower, she probably needs to be in care (or perhaps simply removed from her (feckless?) parents?). There again, we would then be reading some story about how the rozzers had a child taken away and the mother jailed just because the kid didn't want a shower.
Like making peoples life hard much?
*Either as a direct result of the restraint (if a choke/strangle is employed) or from positional asphyxia if a pin is used and kept on for too long.