Greetings, good folks.

I am the new Maintenance Director at a Memory Care facility, and have been tasked with giving a fire extinguisher demonstration complete  with fire.

My question is how do I create a relatively safe fire in a metal trash can or something similar outside that is easy enough to relight for multiple people to get actual "hands on" use of a fire extinguisher? Is there a safer alternative to using gasoline, such as a fire gel? How is this type of demonstration normally performed?

Any tips you can provide would be most welcomed. 

Thank you.

It is usually carried out by specially trained fire extinguisher engineers / demonstrators.  I would contact a few fire extinguisher companies local to you and ask them. 

I understand that you want to demonstrate the correct use of portable fire extinguishers, but I have to ask are you trained to give such information, what would your insurance company say if one of your attendees caused a serious fire? 

Most fire training these days uses LPG fuelled simulators, although there is still some use of live fire using actual fuels (gasoline, paper, etc).

Gasoline is extremely hazardous and isn't advisable (when we still used fuels we used kerosine that doesn't produce flammable vapours until heated).

If you are in the US (a guess from the use of 'gasoline' instead of 'petrol') you are likely to be mainly using dry chemical extinguishers - be aware of the risks of damage and from inhalation with this agent when deciding where to do the training. Also unless you have spares you can't reduse your cover by using your own extinguishers.

As your extinguishers will have to be serviced you will have a fire protection firm in place for this - it's best to ask them for help as they will have spare extinguishers and possibly training kit too.