Spent some time in William-Sonoma yesterday (always VERY dangerous) among our purchases, I convinced my home bartender hubby that we need one of these for fresh whip on our hot toddies. I used it last night, per the enclosed instructions and it works fabulous. Question is, can you add flavoring (like vanilla) and/or sweetener to the cream in the can? Would this affect the quality of the whip foam? What is your experience?