The spit test is pure junk. Only highly ignorant people recommend it ... and the makers of threelac who want to convince the world that everyone has candida.
It has no scientific basis whatsoever. If you go to a reputable lab/nd they will either tell you:
1. Blood test
2. Saliva test
3. Stools test
4. Alcohol challenge test
Stools test is unreliable for candida, as candida is very good at not showing up in the stools. 1,2 test for candida *antibodies* and are the only reliable medical tests for candida. 4 - basically they feed you Sugar and then later test your blood alcohol level. If your body is making alcohol from Sugar then you have candida (or some other yeast/bacteria causing fermentation).
Questionnaire is also pretty reliable (google: candida questionnaire).
Finally a cheap good way to test for candida is to do a vinegar enema - you should see white strands/sheets if you have candida.
As a wise man once said "Spitting into a glass gets you a dirty glass".