Clowns, rap artists and puppeteers are the best way to teach primary school-age children the dangers of taking heroin or crack cocaine.
Evaluators who looked at the success of the first anti-drugs scheme in the UK to target five-year-olds found entertainment was the key to success.
They found an "amazing" 95 per cent of key stage 1 pupils who took part in the programme could remember its messages 12 months later. However, they have recommended it for national roll-out because only pupils from north Wales currently benefit from the programme.
CAIS, a Flintshire-based agency tackling alcohol and drug abuse, uses professional performers from cruise ships to get their Don't Touch - Tell messages across. Peter Davies, a former county council school adviser, helped devise the programme 10 years ago.
He said: "The most important thing is that children find it entertaining.
That way they are more likely to take the messages in."
Children from KS1 and 2 sit through 30-minute shows delivered by entertainers. KS2 pupils are also taught how to deal with peer pressure.
They are told not to touch used syringes, other people's medicines and hard drugs - but also to tell an adult if they come across them.
A spokesperson for St Winefride's Catholic primary school in Holywell, Flintshire, said: "Children enjoyed the performance, which helped to reinforce curriculum work. The content was lively and age-appropriate."
Wepre CP school, in Connah's Quay, also sent feedback back to CAIS. A school representative said: "The children loved it - such an enthusiastic response."
CAIS gave a presentation to the Welsh Assembly last week at the request of Plaid Cymru. Janet Ryder, Plaid's education spokesperson, said: "Don't Touch -Tell is a simple and effective message delivered in an entertaining and appealing way for young children.
"It is the first anti-drugs message many of them hear, and it is important they remember it."
Six north Wales local authorities have signed up to the scheme. Children are provided with a leaflet to take home and discuss with parents.
Evaluators found 86 per cent of children had done so, with 76 per cent reporting they had discussed it with their parents. Nearly three-quarters of parents reported talking to their children about the lesson and leaflet with their children.
More than 80 per cent of parents perceived the programme had helped them keep their children safe. All teachers questioned for the independent study viewed the scheme in a "positive light".