Is daily anal douching safe?

Not safe. No. Destroying your natural rectal and colon environment leads to increasing risk or more dangerous infections or bacteria. Frequent douching increases HIV risks. I know of no physician that would recommend even one douching let alone repeated douching.
Safety. Probably safe but the real question is why bother and go through all that trouble. What's the point?
Anal Douching. By anal douching, I am assuming you are talking about enemas. Enemas should not be harmful, but they also shouldn't be necessary daily. I am wondering what your reason is for doing this. Feel free to submit another question with these specifics.