****e product and not really suitable with the type of plastic the snorkel is made of as the sealant won't adhere to either the snorkel or the bodywork etc. I would suggest seam sealer or Sikaflex as mentioned above.
Then again you could gamble your engine if you want on a £3.99 B&Q special
Don't mean to be disrespectful - I made a similar mistake some time ago and ended up replacing what I had done with proper seams sealant.