I just got a “Make your own hot sauce” kit from a company called Grow and Make. On the back of the instruction booklet, there’s a disclaimer:
Grow and Make does not assume responsibility for the outcome of kits that are not used in ways which are not intended.
I think you put one too many “nots” in that sentence.
You should write them and tell them to get notted.
Wait about 6 weeks. Then you use a kit in a way not intended, blow up your house by doing so, then have your lawyer send them a nice letter saying their supposed disclaimer in fact is clearly an assumption of strict liability. With a suitable bill for repairs attached.
After they have duly had their cow, you could send a nice “April Fools” letter. 
Or one too few.
Grow and Make does not assume non-responsibility for the outcome of kits that are not used in ways which are not intended.
A law-school niece once explained to me the “reasonable person doctrine”. A judge would say that a reasonable person would have understood and been guided by the intended meaning of the disclaimer. My question had been about a motel with a “free breakfast” sign.