Every speck does not need to go- but if you tried to run/start the saw on straight oil, it will be in the tank filter, fuel line and carb- all of which will need cleaned out.
Rinse the tank with mixed fuel, swill it about in there, dump it out in a bucket, refill with fresh mixed fuel and if the filter/line and carb are clear- it should be good to go.
Any residual bar oil left in will mix with the fuel and burn through the system.