Toyota Repair: shifter, brake light switch, soap and water

Question
At times my shifter locks up when I start car (2006 Highlander) have taken it in twice to Toyota dealers, first time said dirt or something has been spilled , they sprayed unit.
second time they looked at me like I was crazy, kept car for better part of day, they said they worked shifter 50 to 100 times and not one time did shifter not operate properly.  I am a retired US Navy Cdr and I don't make up thing that doesn't happen. This doesn't happen all the time, but does at various times, I have to cut off engine and restart some times this works, some times have to do it more then once>  Suggestion

Answer
They were right, this is usually caused by something like a drink that was spilled and entered the center console, anything containing sugar or sugar substitute will cause the shift interlock to malfunction and stick causing it to not come out of park position. The solution is to open the center console shift cover and spray soap and water solution to get rid of the sticky substance but this didn't seem to work. I don't really have an answer either, they may have to replace the entire shifter unit, is it still under warranty?
Has the dealer checked all the computer systems for any trouble codes? If not then maybe that should be the next step as a malfunctioning brake light switch can also cause this, this will show up on a diagnostic trouble code check in history.