I came across this method in New Zealand and it really is a quick and easy no mess method of dyeing wool sliver, fleece and yarn

Requirements
1. Fibre measured into 200gms lots. Fleece, sliver or skeins.
o Larger bags can take more wool but care is required to keep the bag from bursting.
o It is recommended that staples of fleece be washed well first as there is no point in dyeing the dirt that makes up part of the greasy weight of the fleece! That said, raw fleece can be used but does give a different finish.
o Skeins should be tied in 3 or 4 places very loosely.
2. Jam jars for preparing dye liquor. One for each colour used.
o It’s useful to mark 50ml, 100ml, 150ml and 200ml on the outside with a felt pen.
3. (Optional) Squeezy bottles – like washing up liquid bottles - with pouring spouts are also good to deliver the dye onto the fibre and can also be used to store unused mixed dye for another occasion.
4. Acid dyes (Jacquard or Panhue)
5. Accurate scales or measuring spoons kept specifically for dyeing
6. Liquid detergent (wetting agent)
7. White vinegar
8. Plastic bags without holes. Oven bags are excellent and can be reused.
9. Dust mask
10. Rubber gloves
11. Plastic teaspoons
12. Urn or large pot of lightly simmering water (method A)
13. Microwave (method B)
14. Large plastic bowl to fit microwave

Random Dyeing
1. ALWAYS wear a dust mask and rubber gloves while handling dry dye powder
2. Choose dye colours. A light shade can be achieved with a 0.5% dye depth, a strong shade with a 1% dye depth, total saturation at about 2%.
3. A 1% dye requires 2gm of dye to dye 200gms of wool to a medium shade.
4. 1 small tsp of dye powder approximates 1 gm for most colours of Jacquard dyes
 
Method
1. Place 200gms of fibre loosely into a large plastic bag
2. Measure 1 small tsp of dye into a jam jar.
3. Add a small squirt of liquid detergent (about ¼ tsp)
4. Add 2 tblsp of tap hot water
5. Swirl to dissolve (stir with a tsp if necessary)
6. Make up to about 200ml with cold water and add 1 tblsp of white vinegar
7. Repeat with other colours required (three give a really good mix)
8. It takes about 600ml of liquid to effectively and easily wet 200gms dry wool and the addition of liquid detergent is essential. If not enough water is added the colours may run together more than is desired and the wool may begin to felt as the liquor is pushed hard into the wool. The wool may be wetted first and spun out in the washing machine but experience shows that colour variations are more crisp if dry wool is used.
9. Pour the 3 dye colours slowly into the bag, each colour in only 2 or 3 spots - this is much easier with a squeezy bottle. Now push down gently, twisting the neck of the bag a little and excluding air from the bag. Gently push the heel of the hand into the wool to push the dye through. While holding the neck of the bag, turn over and repeat until the wool is just saturated and there are no spongy dry spots.
10. Method A – exclude as much air as possible and tie tightly. Place bag onto the simmering water and time 5 mins – turn over. 10 mins – turn over. 10 mins – turn over. At this point the water in the bag should be clear. If not turn and leave another 10 mins.
Method B – exclude as much air as possible and tie tightly. Place bag into a large plastic bowl and place into microwave. Cook on high for 4 minutes.
11. Leave to cool a little and rinse thoroughly in warm water.