Tried this little system out tonight..... hmmmmm. The quick and easy- couple sports style soft mouthpieces you form with the hot water... Easy. Now you have 10 little blue packets of the whitening gel( which I later found out is a nice name for battery acid!) .... the system calls for 5 applications of 20 minutes each cycle. with a 10 minute rest (COOL DOWN) period... Sounds pretty simple.. so I get started... squeeze one packet in the lower mothpiece, get it in my mouth. Same with the top mouthpiece.... Hmmmm.. After a few minutes a nice staedy stream of drool begins to come out of my mouth... I am thinking "20 minutes- yeah right!" After about 10 minutes, the whitening gel begins to tingle like a redhot mint.... Not bad... I hit the 20 minute mark, rinse out my mouth, and brush my teeth. My mouth felt like it was full of ice, it was tingling..... OK, waited 10 minutes and repeated.. This time I folded up a papertowel and put it between the mouthpieces so I could breath, and attempt to keep my mouth dry... as soon as the gel hit the teeth, the excess went up to my gums and started burning.... This is the part I was unaware of.... that comes later. Well this vicious cycle continues, and the pain feels like a dentist inserting a needle into the gums for deadening..... I make the 20, and haul arse to the bathroom and rinse, brush and try not to put anything cold in my mouth(including AIR)... WOW... only 3 more to go.... I start thinking this SUCKS! Carol says my teeth are lightening up, but I cant see the change.. Ok- one more tonight and continue tomorrow. I make it about halfway thru before the excruciating pain sends me running to the bathroom to spit this overpriced crap out of my mouth.. I rinse with warm water, brush, and observe in the mirror.. WHat I now see is my lower gums at the toothline, on 2 teeth is SOLID WHITE! I thought I just murdered my gums!!!! I ran back in the living room and showed Carol... she lof course laughed, then told me "you arent supposed to get it on your gums!" DOH!!! NOW YOU TELL ME!!! She lets me know the color will come back to what I thought was gonna be dead skin.... WHEW!!! AFter about 5 minutes I got the color back in my gums.... I do believe could empty the liquid acid out of my truck battery, and replace it with this gel..... ANd have a lifetime battery! I feel like my teeth have had aluminum foil rubbed all over them... WARNING!!- USE this crap with caution!!!!