The rice paste is prepared with a creamy consistency, and 'daubed' would be a more appropriate verb than 'sprinkled'.
As the printing process proceeds, the brush does become well charged with a pigment/paste mixture, but it is hard to understand where the idea to 'soak the brush properly with this paste' comes from. Using too much paste results in muddy colours, causes problems with paper adhering to the block, and also leads to excessive shrinking of the paper when drying.