Which remedy should NOT be used if pads dig into the sides of the nose?

The remedy involving toughening the skin with acetone should not be used if pads dig into the sides of the nose. This is because acetone is a harsh solvent that can lead to skin irritation, dryness, and further sensitivity. The objective when dealing with discomfort from pads is to address the root cause of the pressure or irritation, rather than to toughen the skin, which could worsen the problem.

The other options serve to alleviate the discomfort effectively. Changing the pad shape can help distribute pressure more evenly and fit the contours of the nose better. Adjusting the frame fit can relieve points of pressure, making the overall experience more comfortable. Using softer pads can minimize discomfort directly on the skin where the pads touch. Therefore, employing a solution that fundamentally addresses the physical fit and comfort is much more beneficial than trying to condition the skin with a potentially damaging substance like acetone.