Nerve agents and substances causing injury to the skin and tissue are easily soluble in, and penetrate many different types of material, which renders decontamination more difficult. If chemical warfare (CW) agents have penetrated sufficiently deep, then toxic gases can be released from the material for long periods.
To be a jockey, there are no height limits, only weight limits. A rider can be of any height if they can still make weight, but it is still generally limited to fairly short individuals because of the limits on a person's body. Jockeys typically range from 5' to 5'7 in height. No need to lose any weight.
A well-trained racehorse knows the jockey's every movement. The horse knows when to go left, right, faster, slower and when to stop just by the jockey's slight movement. The reason they are effective in the race is because of the time they have spent together preparing for the race.