The above Table 2 shows composition examples for Na/K=70/30. In Test Example 2-1, where in trimethylglycine was not blended, both the solidification point and the hard ness became lower than those ofTest Example 1-1 (Na/K=SO/20), and approached the lower limit for practical use. On the other hand, it can be understood that the solubility by rubbing at a low temperature and the foaming property at a low temperature increase and the usability at a low temperature mcreases.