Flip Flo valve

Hi all,
Hubby had a SP catheter fitted on 2nd August and was wondering whether he could use a Flip-Flo valve when we next have a leg bag change….
1. What benefit is it
2. How long should you open it to empty it
3. How often should it be changed
4. Can you attach overnight bag to it as bag is then washed and attached daily for 5 days.

I am frightened that the closeness to the catheter itself is so close that bugs could enter more easily than having a leg/thigh bag attached to the catheter.

Please let me know how you manage one of these.

Thanks

Lush