If the contamination is in/on/above your LSP you can clay very gently and you might not even have to reapply the LSP. But most people don't clay that gently anyhow.
If the contamination is under your LSP, they you have to "clay through the LSP" to get to it and will thus have to redo said LSP.
You might just consider waiting until the LSP needs refreshed and claying/redoing it then.