Sorry Chis
I don't know about the lwwf rice, but I know that the ordinary rice in bags that can be nuked, can be heated safely in the bag in boiling water. I tore a tiny wee edge of the top corner of a pack and boiled it up. In a micro the John West ones (49p a pack just now in Home Bargains) take two minutes. I put mine into a pot, covered it with hot water and put a lid on the pot. I was using one of the cassette stoves and it was near the end of a cartridge so it was going slow. I reckon I gave it maybe five minutes at most. It came out fine, hot, and wasn't hard. I suspect I didn't need to tear the bag at all, but I was playing it safe.
You could try it at home and see how it works out for you?
cheers,
M