I've never crossed a strain with hemp, but hemp usually has a high lever of CBD iirc. So you'd probably end up with seeds that are lower in THC and higher in CBD than weed, but higher in THC and lower in CBD than hemp. Garbage if you are a rec smoker, maybe not bad if you're a med smoker.
And there'd be a higher likelihood of getting a hermie.
You should find out if there's a hemp field in your area and how far away it is before you start throwing away seeds you had planned on keeping. And find out if your neighbours have a male or hermie if possible.