I hose the pads off before washing them but they still smell like pee after coming out of the washer. What can I do to remove the pee smell? Can I bleach them without ruining the absorbancy?

Hi. You may put a small amount of vinegar as what our other parents do with their washing.

Can they be washed in hot water and bleach?

Please check this out, Hope this helps. https://petparentsbrand.com/pages/washing-instructions  

Do these pads need to be rinsed out before putting into the washer? Also, do they need to be washed after one-time use.

Hi,
Thank you for asking the question!

Our washable pee pads do not need to be rinsed before being put into the washer. 
They do not have to be washed after one-time use. How often you wash the pads will depend on the volume of pet waste + your tolerance. But in general, no they do not need to be washed after every single use. 

I hope that answers your questions.
If you need anything else please don't hesitate to reach out.
Thank You,
Allison P.