I don't recommend pulling the pan without pulling the engine... it's just as much work to pull the engine and you've got so very little room to work and inspect things that it just isn't worth it.
As for making sure the dipstick's inlet is clear get about 4' of 1/8" aircraft cable and SLOWLY feed it in.... Work it in and out, so 2" in and then pull back 1"... so you know it's not going to get hung up.
I don't think it's a clean on the dipstick as you perceive though.
Squirters are only available through Toyota parts dealers as far as I know. I'd try Champion Toyota out of Texas.
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