All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is recommendable to mention Allah's Name at the beginning of ablution. The Prophet said: “The prayer of a person who does not perform ablution is not valid, and the ablution of a person who does not mention the name of Allah (in the beginning) is not valid.” [Abu Daawood, At-Tirmithi and others]
It is also commendable to say the following supplication at the end of ablution: “I bear witness that there is no God but Allah and I bear witness that Muhammad is His slave and Messenger.” [Muslim] Then one adds: “O Allah! Make me from among those who truly repent and make me among the purified ones.” [At-Tirmithi]
As for the Thikr (remembrance of Allah) while performing ablution, some scholars say:
(1) While washing face: 'O Allah! Make my face white when faces become black (i.e. to achieve success on the Day of Judgment)';
(2) While washing hands: 'O Allah! Give me my book in my right hand and not in my left';
(3) While wiping over the head: 'O Allah! Forbid my hair and skin from Hellfire', and
(4) While washing the feet: 'O Allah! Make my feet swift on the Al-Siraat (the bridge over Hellfire)'.
They took evidence for the above-stated supplication from a weak narration reported by Ibn Hibbaan in his At-Taareekh book. They added that it is acceptable to depend on a weak narration concerning doing good deeds. The above action is also reported from some pious predecessors, while others believe that such action is not recommendable since all forms of worship are Tawqeefiyyah (i.e. no one can introduce any practice, rites or principles that are not stated in the Quran or the Sunnah) and the Ahadeeth are very weak in this concern.
Thus, we think that this last opinion is closer to the truth and this is our opinion.
As for the forms of the Athaan (call to prayer) as mentioned in the Hadeeth reported from 'Abdullah Ibn Zayn and recorded by Ahmad and Abu Daawood, they are as follows:
Allahu Akbar: Allah is the Greatest of All (four times). Ash-hadu An-Laa Ilaaha Illa Allah: I bear witness that there is no God but Allah (twice).
Ash-hadu Anna Muhammadan Rasoolu Allah: I bear witness that Muhammad is Allah's Messenger (twice).
Hayyi 'ala As-Salaah: Come to prayer (twice).
Hayi 'ala Al-Falaah: Come to success (twice).
Allahu Akbar (twice).
La Ilaaha Illa Allah (once).
Here, it is essential to state that the Athaan is not allowed in any other language except Arabic unless one is not capable to do so.
Allah knows best.