Yes, pouring boiling water down a drain is generally okay and can be an effective method for cleaning drains. Boiling water helps break down and flush away debris, grease, and soap scum that may contribute to clogs or unpleasant odors. Carefully pour the boiling water down the drain in stages, repeating the process if necessary for stubborn clogs. This method is especially effective for addressing issues caused by soap scum and grease. However, caution should be exercised to avoid splashing, and it may not be suitable for PVC pipes, as prolonged exposure to boiling water could potentially cause damage. If concerns persist, consulting with a professional plumber is advisable for further assistance.