IMHO the most important thing is soft water, whether you use detergent or soap. Calgon or other metaphos is necessary unless your water is less than 50 ppm calcium compounds.

That said, I use 4 buckets to wash a pound of fleece. More than a pound I just keep refilling the buckets.

Bucket 1--add calgon and hot water for presoak

Bucket 2--calgon plus soap or detergent and hot water

Buckets 3 and 4 --hot water to rinse

I have a concrete floored laundry room so I use my washer to spin out the water from all the steps above. By hot water I mean ca. 140ºF. All buckets start out at the same temperature. I use a stick (broom stick, 1x2 etc.) to poke the wool down but no major agitation. I'll pour water and fleece thru a colander then spin the fleece in the washer.

After the wool's dry if it's not clean enough I'll wash it again. I seem to get better results that way rather than doing 2 or 3 soap buckets in a row.