  Tin pest, the allotropic {\beta} - {\alpha} phase transformation of tin, was
examined for use in cleaning of tin-contaminated optics. Induction of change in
material structure led to disintegration of tin samples into pieces and powder.
The transition times were studied for tin drops of different purity grades,
using inoculation with {\alpha}-Sn seed particles, also after prior mechanical
deformation and surface oxide removal. For tin of very high purity levels fast
nucleation within hours and full transformation within a day could be achieved
during cooling at -24 {\deg}C, resulting in strong embrittlement of the
material. Tin dripped onto samples of multilayer-coated optics as used in
extreme ultraviolet lithography machines was made cleanable by phase transition
after inoculation and cooling. The reflectance of multilayer-coated mirrors was
found to decrease by no more than 1% with this cleaning method.
