Technically it's far more sanitary to wash your hands before you use the restroom to have clean hands before you touch a place that is ideal for bacterial growth. And any concerns about the "harder to keep clean" are tossed out the window with basic proper hygiene such as bathing.
Ultimately, it is your argument that fails because you believe reasons that are false to be good reasons to perform a non-medically necessary body modification on a non-consenting child. You believe it is ok to strip the child of autonomy when it is unnecessary to do so, to perform a permanent alteration of their body.
Body modifications should always require consent with the only exception being that it is medically necessary. But if this condition is not met, body modifications are not suitable and should not be performed on children, especially those who cannot consent.
Yes, I believe it necessary to make choices for a child.
Yes, I believe these choices will permanently alter a child's life.
Yes, I believe plenty of research documents that circumcision makes cleaning easier.
The bottom line is, that you can use all the graphic and weighted language you want. Emotional appeals do not change the rationality behind this. Decisions are made for children, and that a decision can be deferred until later does not mean it ought to be deferred until later. I imagine that there are people who complain about the choices their parents saw fit to make. But circumcision does not do lasting harm, excepting of the circumstances when there is error or contamination.
Now, if you have evidence that would somehow show that parents are harming their children, I would listen. But, I do not see a missing foreskin any more harmful than a pierced ear.
I will agree that circumcision is certainly not necessary. And while there most certainly is hygienic benefits, I don't think this hygienic benefit is of any particular great importance. But don't try to imply that these actual, documented, benefits are "tossed out the window." I get that it would be convenient, for them to be tossed out the window. But let's face it, just because a kid gets a cavity does not mean they aren't brushing. People clearly want to dismiss facts. I imagine that the best way to do so, is not saying that the reason for those facts existence is bad parenting and improper hygiene. Rather, try acknowledging those facts and saying whatever hygienic benefit does exist does not outweigh the costs.