Refiners' rhymes with:
refiner's, refiners, refiner's, refiners, refiner's, refiners, decliners, designer's, designers, designers', dinars, diners, liner's, liners, liners', meiners, miner's, miners, miners', minors, niners, niners', refiner's, refiners, reiner's, reiners, shriners, signers, steiner's, whiners
Refiners' sounds like:
refiner's, refineries, refiners, refinery's, revenuers