以往都是 tramp-cleanup-all-buffers 然后 tramp-cleanup-connection，今天尝试直接 tramp-cleanup-connection，发现不会清理 buffer。
根据 Cleanup remote connections (TRAMP 2.7.1.30.1 User Manual)：
Flushing remote connections also cleans the password cache (see Reusing passwords for several connections), file cache, connection cache (see Reusing connection related information), and recentf cache. It also deletes session timers (see Setting own connection related information) and connection buffers.
看上去应该是清理 buffer 的才对，当然也有可能是我理解错 connection buffers 的意思，所以来论坛里问一下确定一下正确的行为是什么。如果它本身确实不清理，我就自己搓/找别的解决方案了。