The answer is likely no. But oral cancers do not start in the throat. Swishing a solution around in your mouth, and gargling with it will pick up cell cast offs from everywhere. Of course no method is 100%.

You have your phraseology a bit off. Cancers of the epithelium like SCC start in the basal cells (not on the surface) and migrate towards the surface epithelium over time. The mucosa is the outermost covering of the upper epithelium in the mouth. Lastly you are assuming that what these test looks for is in the cells, and that is not always true. In the saliva are the protein biomarkers that they are looking for, not in exfoliated cells. Only those that are evaluating cell aberrations as markers care about cells. The Wong/UCLA work is not based on cellular material but proteomics. The proteins that they are interested in are in the saliva, not cells, and therefore that is why salivary diagnostics is more interesting than what is being done on exfoliated cells at other institutions. It DOES find things which are not necessarily on the surface yet.

Brian, stage 4 oral cancer survivor. OCF Founder and Director. The first responsibility of a leader is to define reality. The last is to say thank you. In between, the leader is a servant.