hi, you do know there are different grades of michelin mousses, rally ones are firmer therefore harder to fit. as dick dastardly says keep the speed down, plenty of lube,

on a desert rally with the tenere i did 5,000 miles[2 desert rear tyres] on the same rear mousse, i still occasionally fit it for offroading. it's still in great shape.

the front however was an enduro version, it lasted for about 3,500milesthen went 'off' big style leaving with 200k's left in a 750k day. all i could do was strap it and get the gas on!, i was not aware then that there was a rally spec front

my advice go for it! nothing is worse than a day ruined by punctures or having to back it off due to the fear of compression punctures