The ornamental design for a barbecuegrillbrush, as shown and described.
FIG. 1 is a top perspective view of a barbecue grill brush showing our new design;
FIG. 2 is a bottom perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a right side elevational view thereof, the left side being a mirror image;
FIG. 5 is a rear elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken line circle immediately inside the grill brush pad in FIG. 7 represents the bounds of the claimed design, while all other broken lines are for illustrative purposes only; the broken lines form no part of the claimed design.