After getting your ears pierced you need to disinfect them.
Tips
usage
Interchangeable with 穿耳洞. 打 here is the general 'make / do' sense, the same verb you'd use in 打针 (give an injection). For nose, navel, and lip holes you'd typically say 打鼻钉 / 打肚脐 / 打唇钉 rather than 穿.