I went stiffer yet, expanded metal lath, lath wire. We applied a scratch coat first and then a finish coat later. When the finish coat is thumbprint hard I like to take a damp sponge and lightly remove the "cream" from the surface, exposing more of the aggregate. Everything else sounds like Redover's method.
Your mortar should be at a slight angle in the chink joint. Meaning the top should be inset 1/2" or so with the bottom coming out flush to the log. This creates a drip edge.
That should be written on your shirts front and back
It's been awhile but from memory (and everyone has a different one);
1 part white portland
2.5 parts sharp white sand
1/4 part lime
And repeating John again, mark your buckets, keep your sand covered and mix the same way every batch.
You can try a grout bag, a grout bag with the annoying cone cut out, drywall pan and trowels, whatever gets it on the wall to be tooled. I have no mercy on trowel tools, buy several and shape them as needed with a grinder.
Just for a blast from the past, these are some chink and daub methods from yesteryear.
Corn cob chinking with mud. The rot on these logs was largely caused by the 2 successive coats of lime cement mortar and then a portland chink over this, they had done a bad job tucking the mortar under the edge at the top. This invited water into the middle of the chink joints wetting and rotting the logs. This is the house that had a civil war sword hidden in the chinking.
This one is flakes of stone from the foundation and chimney work, parged with a sand-lime mortar. I like the head trim. You can see a flat split of chestnut driven into the next joint above as a chink and some of the yellowish mortar remaining. The notch would have held a joist.
This one is splits and chips from hewing the logs wedged in the gap and parged over with the same lime-sand mix. Lime whitewash on the logs, nice typical beaded floor joists that had been just as typically been lathed and plastered in some remuddling. The owner of this house remembered using confederate scrip as play money while playing in this house as a girl. All I ever find is the empty mason jars