Right on, with the pine needles in some areas. I also use large wood
shavings that do not contain any walnut with good success.
As a small hobbyist, one of my favorite smoker materials is the berry
clusters from sumac. Be careful that you only collect these that have
upright red /brown berries as there is also a poison sumac with hanging
white/gray berries.
They light easy and seem to have a increased calming effect over regular
smoker fuels. Their downside is they are rather bulky  require refueling
after several hives.
A smoker fuel discussion could go of for ever and it was not my intent ,
only to warn about burlap
Thanks
Dan Veilleux
Vilas, NC