Assalamualaikum,
If my wife is in periods or when she is pregnant and doctors recommend not to have sex, as an alternative can I use silicon-made sex toy for men which is easier to clean and reuse.
الجواب وباللہ التوفیق
This is against nature. It is a shameful act and is impermissible. You must refrain from it.
۔ وَالَّذِينَ هُمْ لِفُرُوجِهِمْ حَافِظُونَ (5) إِلَّا عَلَى أَزْوَاجِهِمْ أَوْ مَا مَلَكَتْ أَيْمَانُهُمْ فَإِنَّهُمْ غَيْرُ مَلُومِينَ (6) فَمَنِ ابْتَغَى وَرَاءَ ذَلِكَ فَأُولَئِكَ هُمُ الْعَادُونَ (7) {سورۃ مومنون}
واللہ اعلم بالصواب