The safest first approach is to hand wash the strap with a mild detergent, using the care label if there is one. That avoids the main risk of a washing machine: straps getting tangled or wrapped around the agitator.

If simple surface cleaning isn’t enough because the padding has absorbed oils or repellent, a machine wash can work, but do it cautiously. Put the strap inside a protective laundry bag or case, and use a gentle cycle. Community experience suggests this can remove the greasy residue successfully.

A dishwasher was also suggested as a gentler alternative, especially on the top rack, but hand washing remains the most conservative option.

So: start with mild hand washing; if the strap still feels contaminated, use a protected gentle machine wash rather than washing it loose.