Using earbuds often pushes earwax deeper, compounding the blockage after swimming. Since olive oil-based drops did not help, you can try over-the-counter ear drops containing carbamide peroxide or a mild 3% hydrogen peroxide solution to help break down the hardened wax. Apply a few drops, tilt your head for five minutes, and then let it drain. Please avoid using cotton swabs or any sharp objects, as they will only compact the wax further. If the blockage remains after a few days or if you develop pain, please see a doctor for a quick and painless professional ear cleaning, such as microsuction.