Another Halo-Chrome attempt

Another attempt at partial indirect toning with Rockland Halo-Chrome. Bleached at 20% of the recommended concentration. Toner has 10% by volume of Ilford Multigrade (1+9) added. When the print is put into the toner it produces a dense black precipitate, which is very difficult to remove. It can be seen in the white border & muddies the highlights :( Any suggestions on how to remove it are most welcome!