Last night I was watching a few minutes of the beauty report and they had a rep on demoing a new foundation made by BeautyBlender...it was a kit with that sponge also and some setting type spray. The rep explained how to use the sponge correctly...she said you MUST get it completely wet until it enlarges with water. Then squeeze it out well...this way when you use it the sponge doesn't soak up so much foundation but instead will lay down the foundation easily.
So I tried my BB sponge again this morning using my Revlon ColorStay foundation dry skin formula (been using this for yrs.) ....I did exactly as she said and it worked really well. I admit I had been squeezing mine in a towel to really get the water out before applying so that was incorrect.
Now with that said I do feel a brush is the easy way to apply and I have several of those that I use most. BUT this worked out great today.
As for cleaning it....I think you need to clean it properly daily...I let mine air dry after use and clean it later in the day when it's dryer. I use a tiny bowl...put a tiny amount of olive oil in it and rub the sponge in it (the part I used and has most of the foundation on it) then I put a nice nickle size amount of DAWN anti-bacterial dish soap and do the same thing...those 2 together breakdown the foundation. Finally I add some HOT water and it usually just comes right out. I rinse and squeeze it out until no more soap and let air dry.
HTH