Stardaddy , I don't know the brand name,if it's 100% pure clear silicone it should be fine.this stuff is real messy so proceed with caution , I have not seen the vidio but it may have some helpful tips
Do not mess with it after you apply a liberal amount . Blue tape might help keep it clean.I worry it could open up the seem.your job will not look as nice as the factory-installed seal.that's o k if it's thick and messy it should hold watter .
I would wait a week for it to fully cure ,fill the tank all the way up being very careful not to spill water,let it sit over night and check for leaks . You could put a filter or power head in it to get some water movement as a added precaution .
This may seem long and tire some but so is breaking down the tank and starting over.
Wish you the best of success