tooth whitener anyone or a no-no?

[neverumind]

Can anyone offer advice on buying tooth whitener. I've bought a proper mouth guard and used the sample bleach, but I would like to buy some online which does a good job and isnt toxic going to do any damage. Thanks!

Go and see a dentist first. Get a full check up and advice.
Regulations have changed in this country and anyone providing tooth whitening who is not a registered dentist is breaking the law.
A 'proper' mouthguard is one made to measure for your mouth, not bought otc.
If you buy chemicals online from an unregistered supplier, there is no guarantee there is mothing 'toxic' in it.