Good concept. Spit, drool, etc. are sadly underutilized in porn.

I can imagine a bukkake/gokkun scene with the lead actress accumulating several loads shot directly into her mouth and then 2-3 fluffer girls adding TONS of their own spit to the mix, with the lead girl mixing it all around in her mouth, swishing it like mouthwash, gargling it until the bubbles billow up out of her mouth and all over her upturned face (having her attempt to inhale the bubbles as they cover her face would be good too).

After the swallow, just repeat the entire sequence over and over until all the guys are drained.

I nominate Sasha Knox, Sierra Sinn, Amber Rayne and Hailey Young as potential human spittoons.