Microbiology - putting fingerprints onto agar

does anybody else do this practical were you put a 'dirty' fingerprint and a 'clean' fingerprint onto nutrient agar plates and leave to grow to see the bacteria/fungi/god knows what(!) grow onto the plates?
We have done it here for a few years but am wondering whether it's actually allowed by CLEAPPS (can't find any literature about it) and also whether it's safe to do so as we don't actually know what's being grown (department has always justified it by saying kids don't open up the plates and they are autoclaved straight after viewing). Would love to hear your experiences :)
Not sure what CLEAPPS suggests but finger dabbing is fine as long as the kids don't rush off and take samples from the toilet seat! As you have said the plates are always taped, not opened and disposed of soon after viewing which sounds just fine to me. I would suggest that work areas are swabbed down and hands thoroughly washed as well.
This is an extract below from Cleapps guidance PS064 "Are we allowed to"

iii) Whether to sample from various places around the school to investigate what might be lurking depends very much on the teacher’s risk assessment of the behaviour and responsibility of the pupils. Sampling, for example, the door knob of the toilets may harvest a bumper crop of coliforms and provide a testimony of the inadequacy of many people’s hand-washing skills. What is sampled from the floor will depend very much on what may be on the soles of everyone’s shoes! A teenager with ripe acne might have a fine collection of Staphyl-ococcus aureus on his/her finger tips. The surface of a hair from the head, however, is probably quite a clean environment but perhaps not so for one extracted from the inside of the nose. A safe (but boring) response is not to sample from anywhere in the environment but this will deny the opportunity of interesting / motivating work and discussions of the importance of good hygiene may not have much impact. If agar plates are sealed with tape around their circumference after incubation (see above), the seal remains intact and the plates are ultimately autoclaved before disposal, risks of infection from unknown pathogens are extremely low. In many classes (but not all), such activities can be entirely safe. It all depends on the teacher’s risk assessment.

iv) 37 °C is certainly a great temperature for many bacteria; they will grow much more reliably and quickly than at, say, 20 °C. But it is, of course, also human body temperature, so incubating agar plates at 37 °C will ensure that what grows inside the Petri dishes can also thrive inside us. All model risk assessments for microbiology work in schools recommend that microbes should be incubated at ambient temperatures, to reduce the chances of isolating pathogens. The advisability of growing bacteria at the higher temperature will again be dependent on the risk assessment and the likelihood of inadvertent accidents or deliberate foul play.
whatever is on their fingers won't kill them (as it hasn't already...) and if it gets them to wash their hands a bit more that's a good thing....
I had to dispose of a set last week which had been left out over half term and they had been not taped up either. One was labelled "girls toilet seat" and had nice red, white and yellow colonies of bacteria on it. I refused to touch them and gave the teacher some sellotape and the autoclave bag.