DE on pool floor

I had a few bad grid on my DE filter. Now there are a lot of DE on the pool floor.
The polaris wont vacuum it becaouse the DE is too small.

1) What is the best way to get rid of it?
2) Can I vacumm in backwash mode so the DE can go directly to sewer instead back into the filter..?

Yes and Yes.

I have no experience with DE filters but the logical approach to me would be to just vacuum the DE back into the filter. Seems too easy. Something must be wrong with my thinking. Wouldn't be the first time.
Al