I tried Swish already and it didn't work for me as it only let me download and view files. I much prefer it over Filezilla or any other standalone client, is there a program that can integrated with Windows Explorer that is compatible with SFTP? I use Windows 8.
Winscp works well for me, and integrates with windows explorer as far as letting you drag and drop to it.
It's not perfect integration, but once you say 'never ask again' to all the confirm dialogs, it's very good.
Since you mention Swish, I suppose by "explorer integration" you actually mean the capability to "mount" the remote SFTP site as a virtual drive (through a kernel driver) or virtual folder (using a namespace extension).
A very good and free solution could be SFTP Net Drive by EldoS.
WebDrive maps a drive letter to SFTP Servers, so it will show up in Windows Explorer as a network drive.