The roof hasn't been opened for quite a while ... OK, not since last year.
When I opened it today, the inside of the roof was covered in mould

I have cleaned it, carefully with a toothbrush (my wife's) and some sterilising liquid, used neat (see below)

It has done the trick, no mould present.
However, there is also mould on the grey canvas, but am I correct in assuming this liquid would bleach the canvas.
is there any other way to remove the mould ?
thanks !
A mate says I should buy one of those wee cheap dehumidifier units, sold for caravans etc. I did think about that last year, but somehow, never got around to buying one. Any advice of these would be appreciated too.