The body isn't positively charged on net. The interior of most cells is negatively charges and the surrounding fluid is OFTEN slightly positively charged which is part of the normal mechanism for material crossing cell boundaries. The whole thing on net is basically neutral. If you're starting from a different position, then the whole idea is baseless out of the gate.
If you had any net charge you'd discharge that into the environment if negatively charged, or vice versa. Usually there's enough humidity in the air to do the trick, but in extremely dry environments static electricity builds up until you touch something like a metal door knob.
If you just wanted some electrons, then generating some static electricity on a rug would be even better.
Even still the amount of current flowing between a person and the earth will be at best minuscule, almost unmeasurable[1]. The idea that "electrons going into your body" this way has any effect on your health is frankly not something that should be taken seriously.
If you had any net charge you'd discharge that into the environment if negatively charged, or vice versa. Usually there's enough humidity in the air to do the trick, but in extremely dry environments static electricity builds up until you touch something like a metal door knob.
If you just wanted some electrons, then generating some static electricity on a rug would be even better.
Even still the amount of current flowing between a person and the earth will be at best minuscule, almost unmeasurable[1]. The idea that "electrons going into your body" this way has any effect on your health is frankly not something that should be taken seriously.
[1]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4241473/