ALTHOUGH many men in our rural area have difficulty accepting women's lib, my husband helps with the housework. One day he took over the vacuuming while I went to the store. The doorbell rang. It was one of his friends, a burly ranch foreman clad in a battered cowboy hat, faded jeans and worn boots. "I was just cleaning," my husband said somewhat abashed, turning off the vacuum. The rancher looked relieved. "That's all right," he said gruffly, handing my husband a white paper bag. "I'm delivering Avon!"