Actually, while it is true that clay can leach out the chemicals in plastic, it does not do so right away and takes some time. Since you will only be spending around 25 - 30 minutes in a clay bath, that time period is not enough time for clay to draw out plenty of chemicals while that amount of time is enough for clay to draw out toxins from your body. Anyway, clay will hold on to the chemicals drawn out from the plastic and it will not transmit these chemicals into and inside to your body. Clay has this tendency to hold to to what it has drawn out and will not just let go. Better take a clay bath than none at all just because of some worries about these plastics.