Pippettes perplex!

Hello Everyone,

I am very new to the lab tech role and loving it. Does anyone have any handy hints about how to stop kids using the same pippettes for different solutions then contaminating stock ... This week I resorted to putting all the chemicals in test tubes in the required amounts... Put a pipette on some solutions (to allow them to practice measuring etc) with making tape, and in test tubes of the chemicals but they still mixed them up!!!!!!!

I mean really???? I don't want to have to resort to bla bla blaaaing at them before the practical.

There must BE ANOTHER WAY!!!!
Place the pipette in the stock solution then strategically place the other stock samples at various points round the lab (far enough apart to make it too hard for them to take the pipette to the next stock sample) and tell them to only use that pipette to get their sample and LEAVE it in the stock. You could even fix the pipette with string and tape so it can only be put in the correct solution.
I use long elastic bands to attach the pipette to the neck of the bottle . You can also attach a small test tube to the bottle and use this as a holder for the pipette.