I'm with Jaz. NEVER put a step inside or outside a tub!
1. They will be slippery when wet. VERY DANGEROUS!
2. They make the two bottoms of the opposite sides of the tub wall different heights. This will throw off your brain and create a fall hazard.
"True eloquence consists in saying all that is necessary, and only that which is."
François Duc de La Rochefoucauld