gum tree sap

You could try eaucalyptis oil - but why not leave it as part of the experience - if we cleaned ours we would not have some of the memories of where and when we got that spot - or that lot of red dirt stain etc. We love the fact that it shows we use if well - and nothing gets through - even in the wettest of weather.

Some friends had their first experience of heavy rain over Easter in their camper - were very pleased at the fact that everything was bone dry - and there is nothing better than lying in bed listening to rain outside knowing you are warm and dry inside. Though I will say, we sometimes put a camp blanket (the type with the rubber backing) over our bed - rubber side up - stops the cold coming through, and adds a bit of extra warmth when needed.
jules

Having had this several times over 30 odd years with our hard floor campers and tents it is best to leave it alone. Some will eventually harden and flake off when dry, some will stain the canvas which you can do nothing about.
Best not to camp under trees especially eucalypts if you don't want marks on canvas, tarps or vehicles.