Proper drying and curing will ensure maximum potency of the marijuana you have grown. Marijuana is not fully potent just after harvest. Some of the THC is in a non-psychoactive acidic form. Drying marijuana the right way will convert the non-psychoactive acidic compounds into psychoactive THC. This does not happen overnight and it would not happen as quickly as buds would dry in rice, with the moisture in the bud being drawn out by the dry rice.
When you use something to speed up drying, to quickly draw moisture from buds, as drying in rice would be an example of, the outer portion of the buds will dry quicker than the inner part, and the taste will suffer.
There can also be the experience of ending up with rice-covered bud because the rice stuck to the trichome-heads/resin-heads and then you get to pick or brush them off, losing trichome heads or parts of them in the process.
Add those up and that is why people do not dry in rice .... something I feel confident was first tried back in about 1250AD, and a few thousand or more times since, until you managed to come up with the idea thanks to a tip from a friend in regards to cell phones.
