Not tried by me - but my Dr Sears (who had 8 kids) book says this:
Hide the medicine in a sandwich
Make a cheek pocket - cradel the babys head in the crook of your arm encircling cheek. Use fingers to pull out the corner of the mouth and drop medicine in pocket. Then apply traction on the baby cheek to keep the medicine from being spat out.
Numb the tongue - sucking on an ice can numb taste buds!!
Sit on your child (sounds rough but if you are desparate) put childs head between your legs. Holding the nose will encourage swallowing. Speak calmly and in a soothing voice!
Can you squirt it in maybe.. into the cheek region is supposed to be the best place to aim
Take care