Perhaps Temples can make some code (or rules). Anyone nationality can enter the temple by abiding the rules.
Foreigners don't even know that during the 'menstrual cycle' they shouldn't enter the temple. A simple dress code is also good (e.g. sari or salwar..etc).
Some foreigners may want to visit the temple just to see what is inside. We can't say that it is picnic spot. They might be just curious.
I think stopping is not a good idea. Because in Indian we give equal rights to all human beings (men or women).
